Means for mounting an adding and subtracting device on slide rules



C. KBLER April 4, 1939.

MEANS FOR MOUNTING AN ADDING A Filed Jan. 6, 1937Iv partially broken away Patented Apr. `4, 1939 MEANS FOR MOUNT ING AN ADDING AND SUBTRACTING DEVICE ON SLIDE RULES Carl Kbler, Berlin, Germany Applicatilr: anuary 6,- 1937, Serial No. 119,349

The present invention relates rule with addition and subtracti multiplications, the divisions an culations by means of a slide rule. Such calculaadditions and subtlons do however also involve tractions.,

1t is inconvenient, that additions and subtractions cannot be made by means of lt has been proposed to perf subtractions by means of a calculating machine, but ii such a machine is used the calculator must at each addition and subtraction put aside the rule in order to be able to manipulate the other device.

The chief object of the present invention is` to remove this deficiency and to combine a slide rule and a calculating machine in such a manner, that they form an integral body, so that the calculator easily may. change over from one A device of this kind must fulfil the following conditions or requirements:

for performing additions and snbtractions must form an element of the calculating rule and must be as flat and narrow as possible. t must not impede the manipulation It must be possible to rapidly remove the addition and subtraction device from and again attach it to the rule when repairs or the like are required. The device by means of which the additions and subtractions are performed must also be so arranged, that it can be manipulated without difficulty, and means must be provided in the rule for stylus by means of which the addition and subspecies to another.

The machine of the slide rule proper.

traction device is operated.

. A constructional form of the trated by way of example in the accompanying drawing.

Fig. 1 shows an embodiment of the invention in which the adding and subtracting device and the stylus are held on the rear side of the rule by means of a plate of Celluloid.v The plate is to show the stylus in its Seat.

Fig. 2 is a longitudinal sectional view taken on line II--II of Fig. l.

to a calculating on device.

it is commen use, not only at culations, but also whenestimations of costs and prices, lists of contract work, performance calculations and the like are made, to perform the d proportion calorm additions and invention is illusthe adding and ermany January 28, 1936 3 Claims. (CL 235-70) rule proper.

technical cal- Fig. 7 is a perspective view of the stylus.

Fig. 6 is a perspective view of the calculating ln the embodiment shown in Figs. l to 6 the slide rule consists as usual of a rule body a3 of `5 wood in which the setting slide a4 is resiliently arranged. Both sides of the member a4 are covered with strips of ivory, Celluloid or the like. The upper face of the rule and the vertical and the inclined sides of the rule are covered with 10 the slide rule.

slide a5.

serve as guides for the cover a9.

and subtracting device f2.

culating legends.

easily be engaged through the notch lc in cover and be reciprocated.

receiving the I2 may be arranged.

and removed from its seat l.

I claim:

strips ci the same material carrying scales, legends and the like. The rule has also the usual guides for the setting slide a* and the filament The lateral walls a5 and c'l are at their lower l5 ends bent inward and form flanges a, which The back side of the rule body a3 has intermediate its ends a recessed part al adapted to receive the adding After the adding i0 and subtracting device has been inserted it is securely held in the proper position between the inner wall al1 of the recess al and a stop The cover a has a window or opening i of such form and size, that all parts needed for the ma- 2F nipulation of the device and the performing of the calculations are visible and accessible. The edges of the opening i in a way form a frame for the addition and subtractionv device and the calso Notches 'it at the ends of the cover a9 facilitate the manipulation of the setting slidev a4 and the setting of the zero slider r3. The zero slider can the 8 In one end of the rule body a3 a groove l is provided which serves as a seat for the stylus p. The stylus is resiliently held in its seat by the cover a9 and ii desired also by means of a spring.

At the bottom of the groove a small metal plate 40 At one end of the stylus a circular groove p1 is formed, so that the stylus without difficulty can be gripped with the fingers The cover a9 is held loosely and with play be- 45 tween the guides a. whereby the resiliency of the bottom of the rule body is maintained. This arrangement also facilitates the removal and remounting of the adding and subtracting device.

'1. Means for mounting an adding and subtracting device comprising, an elongated body member having a recess formed in one face thereof, a relatively dat adding and subtracting device arranged in said recess, a danse extend- I 10 in one tace thereof and extending to one end yoi' tending upwardly from the bottom of the recess 10 15 tending upwardly from the bottom of the recess flanges so as to maintain the adding and sub 1r, engging the other end of the adding and subtracting device in the recess, and said plate-like tractlng device, a ange extending along each cover having an opening therein exposing a por side of the recess. a, plate-like cover engaging said tion of the adding and subtracting device.

v th n 20 tracting device in the recess, and said plate-like CARL KHLER. 2n 

